The present invention relates to methods for making semiconductor devices, in particular, semiconductor devices that include high-k gate dielectric layers.
MOS field-effect transistors with very thin silicon dioxide based gate dielectrics may experience unacceptable gate leakage currents. Forming the gate dielectric from certain high-k dielectric materials, instead of silicon dioxide, can reduce gate leakage. As the thickness of such a high-k gate dielectric is reduced, however, silicide formationxe2x80x94which may result from high temperature processing that follows gate dielectric formationxe2x80x94may cause the device to short through the dielectric.
Accordingly, there is a need for an improved process for making a semiconductor device that includes a high-k gate dielectric. There is a need for such a process that can produce a device that includes an ultra thin high-k gate dielectric that is not shorted through the gate dielectric. The method of the present invention provides such a process.